Blocking Steganosonic Data In Phone Calls

psyced writes "Steganography is a technique to encode secret messages in the background noise of an audio recording or photograph. There have been attempts at steganalysis in the past, but scientists at FH St. Pölten are developing strategies to block out secret data in VoIP and even GSM phone calls by preemptively modifying background noise (link is to a Google translation of the German original) on a level that stays inaudible or invisible, yet destroys any message encoded within. I wonder if this method could be applied to hiding messages in executables, too."

Comments

Re:Or..

[kvezach]

Or perturb the logic. The easy way is just to look at how polymorphic viruses did it. The hard way is to get out your disassembler and change

cmp eax, edx
jle offset
to
cmp edx, eax
jae offset
(insert your own variation here). Have a program read all cmp eax, edx (or cmp edx, eax) opcodes and output 0 for the first and 1 for the second.